Technical Field
The present disclosure relates to transmission and reception devices that transmit and receive high-frequency signals in different frequency bands with the use of a single antenna.
Currently, along with the reduction in the size of communication devices, various configurations for transmitting and receiving a plurality of types of high-frequency signals in different frequency bands with the use of a single antenna are designed. For example, according to Patent Documents 1 and 2, a transmission circuit and a reception circuit are connected to an antenna with an antenna duplexer interposed therebetween. The antenna duplexer transmits a high-frequency signal (transmission signal) from the transmission circuit to the antenna and transmits a high-frequency signal (reception signal) from the antenna to the reception circuit.
In addition, the transmission and reception device described in Patent Documents 1 and 2 is provided with an adjustment circuit that adjusts the characteristics of the antenna duplexer in order not only to transmit and receive a set of a transmission signal and a reception signal but also to transmit and receive a transmission signal and a reception signal that are in another frequency band. The characteristics of the antenna duplexer are adjusted by changing the element value of the adjustment circuit, and transmission of transmission signals having various frequencies and reception of reception signals having various frequencies are achieved.
Patent Document 1: U.S. Pat. No. 8,208,865
Patent Document 2: International Publication No. 2013/149227